Conventionally, a cartridge type recording medium has been known, in which a disc is accommodated inside a cartridge for preventing the disc from being contaminated or damaged due to dusts or the like. Information related to the state of such recording medium can be detected, for example, according to a condition of an opening formed in the cartridge. For instance, information can be written on the recording medium if the opening is in an opened condition, whereas information cannot be written on the recording medium if the opening is in a closed condition. Additionally, a recording medium having a hole formed in a cartridge has been known, the hole indicating a state or type of the recording medium.
There has also been known a disc drive which can house the above-described cartridge type recording medium (e.g., Patent Document 1). The disc drive disclosed in Patent Document 1 includes a servomechanism chassis provided with a turntable for rotatably holding a recording medium and a pickup for recording/reproducing information on/from the recording medium. A base end of the servomechanism chassis is pivotally supported such that the rotation force is vertically applied. Conventionally, a switch section of a lead-in detection switch, write-protect switch, cartridge detection switch, or the like is provided on a tip end of the servomechanism chassis. Owing to this, vertical movement of the servomechanism chassis in a cartridge direction allows some of the switches to detect an information hole formed in the cartridge.
[PATENT DOCUMENT 1] JP-A-9-259498 (4 page, FIGS. 4, 5 and 6)